TUESDAY, May 14 (HealthDay News) -- Women who have a hysterectomy are not in danger of increasing their risk of cardiovascular disease later in life, a new study says.

Although earlier research had found higher chances of cardiovascular disease in the years following a hysterectomy, different criteria were used in this latest study, the researchers noted.

"If women are contemplating hysterectomy, they don't need to be worried about increased cardiovascular risk," said study author Karen Matthews, a professor of epidemiology and psychology at the University of Pittsburgh.

A hysterectomy is a surgical procedure that removes the uterus; sometimes the ovaries are also removed, to lower the risk of cancer.

Unlike other studies, however, the new research included only women who had a hysterectomy in midlife and who didn't have their ovaries removed due to cancer, Matthews explained.

"It is possible that women who have a hysterectomy when they are young have an increase in cardiovascular risk," she noted.

The report was published May 14 in the online edition of the Journal of the American College of Cardiology.

To see if a hysterectomy actually increased a women's risk for cardiovascular disease, Matthews' team collected data on more than 3,300 premenopausal women who took part in a national study on women's health.

They compared cardiovascular risk factors before and after the women had elective hysterectomy with or without ovary removal with women who had a natural menopause.

Matthews' group found there were changes in cardiovascular risk factors after a hysterectomy, compared to risk factor changes after natural menopause.

These changes, however, were not associated with an increase in the risk of cardiovascular disease. Women who had a hysterectomy with removal of ovaries did tend to gain weight, the researchers found.

These effects were similar in all ethnic groups.

It's not known why these findings differ from other studies. The researchers speculated that differences in their study -- such as excluding women who had a hysterectomy because of cancer and the older age of the women -- may have played a role.

The women in this study were middle-aged and it is possible that women who have a hysterectomy earlier may have more cardiovascular risk, they explained.

One expert agreed that the evidence on a possible association between a hysterectomy and an increased chance of heart trouble has been mixed.

"Prior studies have suggested that there may be increases in cardiovascular risk after women undergo hysterectomy, particularly if accompanied by removal of the ovaries," said Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles.

However, other studies have not found elevated risk for cardiovascular events with hysterectomy with or without the removal of the ovaries, he added.

"These findings suggest that hysterectomy with or without removing the ovaries does not appear to play a major role in worsening cardiovascular risk factors in women compared to natural menopause," said Fonarow.

"Nevertheless, as cardiovascular disease remains the leading cause of death in women, women should closely assess, monitor and improve their cardiovascular health," he said.

SOURCES: Karen Matthews, Ph.D., distinguished professor, psychiatry and professor, epidemiology and psychology, University of Pittsburgh; Gregg Fonarow, M.D., professor, cardiology, University of California, Los Angeles; May 14, 2013, Journal of the American College of Cardiology, online